How the Odds Are Calculated at the Sportsbook


A sportsbook is a business that accepts wagers on various sporting events. The company is also known as a bookmaker, and it makes money by setting odds that make winning bets profitable in the long term. These odds are based on the probability that an event will occur and the likelihood that the event will be won by the team or player favored by the betting public. These odds are released as soon as the sportsbook receives a sufficient number of wagers. The odds are adjusted periodically to reflect changes in the probability of winning and losing.

A straight bet is the most common type of sports wager. It is a wager on a single outcome of a game, such as the winner of an NBA match or a UFC fight. The sportsbook sets the winning odds based on its assessment of the probability that the event will happen, which is determined by the margin of victory between two teams or fighters.

It is important for the astute sports bettor to understand how these odds are calculated and how large of a deviation from the theoretical optima is required to permit positive expected profit. In order to answer this question, the CDF of the actual median margin of victory was estimated for a set of matches, and the corresponding probability-weighted expectation of a unit bet on the team with the higher expected value against the sportsbook’s proposed spread was computed. The results are shown in Fig 4, with the height of each bar representing the estimated expected profit for different offsets of the true median margin of victory from the sportsbook’s proposition (i.e., for deviations of 1, 2, and 3 points in each direction).